This chunker looks so easy to make compared to other types. Has anyone used something like this to feed a gasifier?
Rindert
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Cody, it’s true, I make fuel with a screw cutter, … it cuts up to 8 cm thick, but I intend to make a bigger one up to 20 cm thick
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I’m really glad you found that. 
That is my favorite style of chunker since it has built in autofeed and lower HP requirements, and anything bigger goes to the firewood pile. Although I think I will try to figure out how to add a safety bar to it to kick it out of gear. chunking up wood isn’t worth risking losing a hand.
@Tone since you are the resident genius of these. Is that just a cast steel waterpipe for the tube? And how do you harden the edges? It looks like he used mild steel in the video for the auger flights.
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This one looks more your style…
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Since it just clicked that hydraulic rams use hardened steel, would a repair shop that rebuilds these have scrap available like bent ones that could be shortened?
I don’t think I have a motor with a long enough shaft.
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They used to, I’m seeing more shops fixing them now instead of replacing them as the economy noose tightens
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Tone you must be thinking while you sleep to come up with all this stuff. 
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I will ask. A lot of shops may not deal with fixing the shaft because of liability. The cheap used hydraulic rams on CL are all bought up, and refurbished around here as near as I can tell. But I need to do some maths to figure out how long and how thick of shaft I need. a rough guess is maybe an inch and probably about 20-24". I also have to figure what I am going to use for the tube itself. I am guessing 8" minimum diameter and 10" would be closer to ideal. anything bigger then about 3" goes on the firewood pile.
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Are you making a screw chunker?
I’ve been thinking about it. I have material from a 9" oxygen cylinder and an axle shaft from a 1998 Bronco.
The axle shaft has been tempered, so I’ll have to heat it and let cool slowly. The cylinder should be very corrosion resistant, and not brittle, I think.
I’d be careful if you plan to weld to anything tempered. It might tear away or warp. Do a test first. Reheat and oil quench if you feel the need. A makeshift forge is fairly easy to make. Ask me any questions.
Rindert
5 Likes
I’m trying to figure out if I can, and how much it will cost. I have an axle half shaft come to think of it.
What I was -thinking- about doing was to sliding a pipe over the shaft because I know I can’t weld the shaft. 
so the shaft is just to provide rigidity. Then rather then try and machine with no tools to put in a shearpin or key the shaft. just run the bearings on the pipe. and then I can switch pipes if the flights don’t work, and bang out the shaft. The shaft would be a better bearing surface, but I am looking at hundreds of hours not thousands. That is my current thought, not sure if it is worth a crap at this point.
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Not sure what you are thinking but, I would just use the pipe and not use the shaft if possible.
I hear you say you don’t have a lathe?
This will be a PITA, but there is a workaround. Search: centerless grinding
Rindert
4 Likes
just take a design using pipe, and put the hardened steel rod down the middle. The purpose is solely to prevent the flexing of the pipe (I could pour cement or abs plastic down the middle, but I don’t think I would get the same strength) The only drawback I see right at this moment is the torque might twist the pipe.
That video rocks. I don’t think I have never seen a video that used the vice to hold the grinder that makes it simpler even though it is all pretty sketchy using the clamps to hold it… lol
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Think about the drive shafts trucks use. They are tubes. With the design you propose the outer pipe will have to break before the inner shaft has a chance to do anything. I am a mechanical engineer, but of course you don’t know me. I recommend you talk to a mechanical engineer you know and trust.
Rindert
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I trust you Rindert. Good point about the drive shaft. Nothing you are going to build is going to exert more torque than it takes to break the slicks loose on a drag race burnout.
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You guys . . . . sheez.
A driveline car, truck, ship is twisting torque delivering.
A screw auger is this too; but much more side thrusts power delivering. Side thrust power is how it auger shear cuts.
A hollow tube? You are nuts.
Bring up videos of the already developed commercial sold systems in eastern Europe. Big thick solid steel shafts. Whether these were determined by engineering testing and loading charts; or trial and error . . . BIG, THICK, and SOLID.
Steve Unruh
5 Likes
https://www.laimet.com/hakkurit/hakkrrin-terat/
their site → Chippers → Screw Selection for pictures and charts
Thier smallest “household” system
https://www.laimet.com/hakkurit/hakkuri-ps-10/
S.U.
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Duely noted. (20 characters)
This video nicely shows how strong the construction must be
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Hypnotic mesmerizing to watch.
And so, so simply stout.
S.U.
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